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    <meta charset="UTF-8">
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    <title>Document</title>
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<body>
    <script>
        // 非捕获组
        var reg = /kid is a (?=doubi)/;
        console.log(reg.test('kid is a doubi'));
        console.log(reg.test('kid is a shabi'));

        var reg = /kid is a (?!doubi)/;
        console.log(reg.test('kid is a doubi'));
        console.log(reg.test('kid is a shabi'));
    </script>
</body>
</html>